Simplify alternate repo/branch installation

tests/lib/all.sh

@@ -1,20 +1,20 @@
 #
 # source all lib scripts
 #
-# from your script, supply the path to this directory as the first argument
-#
-#    eg source "tests/lib/all.sh" "tests/lib"
+#    eg source "tests/lib/all.sh"
 #
 # failure to load any script is fatal!
 
-. "$1/color-output.sh" || exit 1
-. "$1/locations.sh"    || exit 2
-. "$1/misc.sh"         || exit 3
-. "$1/rest.sh"         || exit 4
-. "$1/system.sh"       || exit 5
-. "$1/carddav.sh"      || exit 6
+D=$(dirname "$BASH_SOURCE")
 
-. "$1/populate.sh"     || exit 7
-. "$1/installed-state.sh" || exit 8
-. "$1/totp.sh"         || exit 9
+. "$D/color-output.sh" || exit 1
+. "$D/locations.sh"    || exit 2
+. "$D/misc.sh"         || exit 3
+. "$D/rest.sh"         || exit 4
+. "$D/system.sh"       || exit 5
+. "$D/carddav.sh"      || exit 6
+
+. "$D/populate.sh"     || exit 7
+. "$D/installed-state.sh" || exit 8
+. "$D/totp.sh"         || exit 9
 

tests/lib/system.sh

@@ -1,3 +1,6 @@
+#
+# requires:
+#    scripts: [ misc.sh ]
 
 wait_for_apt() {
     # check to see if other package managers have a lock on new
@@ -140,3 +143,32 @@ exec_no_output() {
     [ $code -ne 0 ] && return 1
 	return 0
 }
+
+git_clone() {
+    local REPO="$1"
+    local TREEISH="$2"
+    local TARGETPATH="$3"
+    local OPTIONS="$4"
+
+    if [ ! -x /usr/bin/git ]; then
+        exec_no_output apt-get install -y git || return 1
+    fi
+
+    if ! array_contains "keep-existing" $OPTIONS || \
+            [ ! -d "$TARGETPATH" ] || \
+            [ -z "$(ls -A "$TARGETPATH")" ]
+    then
+        rm -rf "$TARGETPATH"
+        git clone "$REPO" "$TARGETPATH"
+        if [ $? -ne 0 ]; then
+            rm -rf "$TARGETPATH"
+            return 1
+        fi
+    fi
+
+    if [ ! -z "$TREEISH" ]; then
+        pushd "$TARGETPATH" >/dev/null
+        git checkout "$TREEISH" || return 2
+        popd >/dev/null
+    fi
+}